diff --git a/CHANGELOG.md b/CHANGELOG.md
index be58657a0..07696a739 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -56,6 +56,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Modified `UserIdleProcessor` to start monitoring only after first
+  conversation activity (`UserStartedSpeakingFrame` or
+  `BotStartedSpeakingFrame`) instead of immediately.
+
 - Modified `OpenAIAssistantContextAggregator` to support controlled completions
   and to emit context update callbacks via `FunctionCallResultProperties`.
 
@@ -79,6 +83,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fixed `UserIdleProcessor` not properly propagating `EndFrame`s through the
+  pipeline.
+
 - Fixed an issue where websocket based TTS services could incorrectly terminate
   their connection due to a retry counter not resetting.
 
diff --git a/src/pipecat/processors/user_idle_processor.py b/src/pipecat/processors/user_idle_processor.py
index 8f40fd52e..3a7202c80 100644
--- a/src/pipecat/processors/user_idle_processor.py
+++ b/src/pipecat/processors/user_idle_processor.py
@@ -12,7 +12,6 @@ from pipecat.frames.frames import (
     CancelFrame,
     EndFrame,
     Frame,
-    StartFrame,
     UserStartedSpeakingFrame,
     UserStoppedSpeakingFrame,
 )
@@ -20,10 +19,24 @@ from pipecat.processors.frame_processor import FrameDirection, FrameProcessor
 
 
 class UserIdleProcessor(FrameProcessor):
-    """This class is useful to check if the user is interacting with the bot
-    within a given timeout. If the timeout is reached before any interaction
-    occurred the provided callback will be called.
+    """Monitors user inactivity and triggers callbacks after timeout periods.
 
+    Starts monitoring only after the first conversation activity (UserStartedSpeaking
+    or BotSpeaking).
+
+    Args:
+        callback: Function to call when user is idle
+        timeout: Seconds to wait before considering user idle
+        **kwargs: Additional arguments passed to FrameProcessor
+
+    Example:
+        async def handle_idle(processor: "UserIdleProcessor") -> None:
+            await send_reminder("Are you still there?")
+
+        processor = UserIdleProcessor(
+            callback=handle_idle,
+            timeout=5.0
+        )
     """
 
     def __init__(
@@ -37,40 +50,72 @@ class UserIdleProcessor(FrameProcessor):
         self._callback = callback
         self._timeout = timeout
         self._interrupted = False
+        self._conversation_started = False
+        self._idle_task = None
+        self._idle_event = asyncio.Event()
+
+    def _create_idle_task(self):
+        """Create the idle task if it hasn't been created yet."""
+        if self._idle_task is None:
+            self._idle_task = self.get_event_loop().create_task(self._idle_task_handler())
 
     async def _stop(self):
-        self._idle_task.cancel()
-        await self._idle_task
+        """Stops and cleans up the idle monitoring task."""
+        if self._idle_task is not None:
+            self._idle_task.cancel()
+            try:
+                await self._idle_task
+            except asyncio.CancelledError:
+                pass  # Expected when task is cancelled
+            self._idle_task = None
 
     async def process_frame(self, frame: Frame, direction: FrameDirection):
+        """Processes incoming frames and manages idle monitoring state.
+
+        Args:
+            frame: The frame to process
+            direction: Direction of the frame flow
+        """
         await super().process_frame(frame, direction)
 
         # Check for end frames before processing
-        if isinstance(frame, StartFrame):
-            self._create_idle_task()
-        elif isinstance(frame, (EndFrame, CancelFrame)):
-            await self._stop()
+        if isinstance(frame, (EndFrame, CancelFrame)):
+            await self.push_frame(frame, direction)  # Push the frame down the pipeline
+            if self._idle_task:
+                await self._stop()  # Stop the idle task, if it exists
+            return
 
         await self.push_frame(frame, direction)
 
-        # We shouldn't call the idle callback if the user or the bot are speaking
-        if isinstance(frame, UserStartedSpeakingFrame):
-            self._interrupted = True
-            self._idle_event.set()
-        elif isinstance(frame, UserStoppedSpeakingFrame):
-            self._interrupted = False
-            self._idle_event.set()
-        elif isinstance(frame, BotSpeakingFrame):
-            self._idle_event.set()
+        # Start monitoring on first conversation activity
+        if not self._conversation_started and isinstance(
+            frame, (UserStartedSpeakingFrame, BotSpeakingFrame)
+        ):
+            self._conversation_started = True
+            self._create_idle_task()
+
+        # Only process these events if conversation has started
+        if self._conversation_started:
+            # We shouldn't call the idle callback if the user or the bot are speaking
+            if isinstance(frame, UserStartedSpeakingFrame):
+                self._interrupted = True
+                self._idle_event.set()
+            elif isinstance(frame, UserStoppedSpeakingFrame):
+                self._interrupted = False
+                self._idle_event.set()
+            elif isinstance(frame, BotSpeakingFrame):
+                self._idle_event.set()
 
     async def cleanup(self):
-        await self._stop()
-
-    def _create_idle_task(self):
-        self._idle_event = asyncio.Event()
-        self._idle_task = self.get_event_loop().create_task(self._idle_task_handler())
+        """Cleans up resources when processor is shutting down."""
+        if self._idle_task:  # Only stop if task exists
+            await self._stop()
 
     async def _idle_task_handler(self):
+        """Monitors for idle timeout and triggers callbacks.
+
+        Runs in a loop until cancelled.
+        """
         while True:
             try:
                 await asyncio.wait_for(self._idle_event.wait(), timeout=self._timeout)